An exoplanet, or also called an extrasolar planet, is a planet that appears within our own Solar System and circles around a star that is varying from the Sun. The prevailing numbers of planets that have been discovered are planets that are consisted of mainly gases, because they are simpler to discover rather than planets that are more like Earth. Detecting these extrasolar planets are probably the most difficult to perceive because they are not seen by the naked eye, therefore making it quite tough to achieve finding them. The difference between exoplanets and the planets inside of our solar system are that most planets are capable of being viewed through at least a telescope, with the naked eye, without the means of some greater viewing capability that is greater than just a regular telescope. Just exactly how do we detect an exoplanet? This process is extremely difficult and has taken quite a long time to detect, even with our latest and most up-to-date technology. An orbiting exoplanet lets off a gravitational force onto its host star; it cause a force that tugs the star in a round or egg-shaped course. The most efficient method scientist’s use is the Doppler Planet Detection Method. This method involves breaking down the wobbling a star has in its movement. Now, before getting too caught up in learning about exoplanets, it’s time to explain just exactly how and when these extravagant beings came to be.
2 Methods for Finding Life
Life on exoplanets is a whole new story. It is almost “impossible” to be able to guess whether or not there is life on these amazing discoveries. There are several methods that scientist’s use to search for life. A few methods are used to spot the possibility of liquid that could thrive on exoplanets. A method used is called spectroscopy; this can show the characteristic absorption wavelengths of liquid molecules. This method actually has been used and worked successfully on giant solar planets that can be reached from reasonable distances from Earth. Other methods that are used include seeking for the appearance of clouds or the tiniest of light that shines off of a reflective surface from the planet. Although, this method has only been utilized for other types of liquids, such as the methane that is on the moon Titan, which circles around our planet Saturn.
2.1 Recent Study Methods
A more recent method that has been discovered could help further the great search. This method, which involves studying how colors shift with an exoplanet’s rotation, could help in the quest for discovering extraterrestrial life. This design should boost the chances of finding exoplanets with oceans — and, therefore, with life. “Since water is thought to be a prerequisite for life, we have effectively proposed another test for habitability,” said scientist Nick Cowan, from the University of Washington in Seattle. The researchers involved with creating this method developed it using data from Deep Impact, which is a NASA space probe that was launched in January 2005 to study the composition of a comet orbiting the Sun. Following the success of Deep Impact a few months later, it was sent on an extended mission to study another comet as well as distant exoplanets. During this extended mission, Nick Cowan and his colleagues used the “high resolution imager” telescope on Deep Impact to examine Earth from a few tens of millions of miles, as though our planet were an exoplanet.
2.2 Study Methods Involving Earth
The primary color of Earth is grey with a bit of blue due to Rayleigh scattering of sunlight off of the atmosphere. However, the researchers found that where the sky is clear of clouds that the average color changes with the Earth’s rotation. Whenever the continents are in view, the color alters towards the red end of the spectrum, and when the sea is in sight, the color alters even more so into the blue. With these transitions of color scientists should be able to reveal and locate oceans on real exoplanets. “The upshot [over the other methods] is that we don’t need very much spectral resolution — a few different filters would suffice — but we need pretty short exposures so that we can track time-variability,” Nick Cowan said. However, to able to view possible oceans on Earth-sized exoplanets, with the closet being at least several light years away, astrophysicists need a much larger telescope to be able to fully complete their project.
2.3 A Greater Telescope
The telescope to be able to view exoplanets would need to be massive enough and possess a corona-graph to block out the light shining from the exoplanet’s host star. But there might be a greater possibility to see oceans on giant Earth-sized exoplanets. Researchers hope to achieve building such a telescope by around the year 2017. A group called New Worlds will assemble a giant, 4m diameter telescope, with a very large corona-graph, to be able to specifically work with the detection of exoplanets.
3 Orbits of Exoplanets
Another exquisite quality that exoplanets have is the source that they use for their own “sunlight”. Each exoplanet that comes inside of our Solar System begins to orbit around a star that is within our own. Researchers even refer to these planets with the name “Alien” simply based on them coming from unknown places. Most exoplanets orbit stars close to the Sun. Observations have shown that stars of certain spectral categories, that stars of certain special categories, that are much warmer than even the Sun, produce a photo-evaporation affect that contributes to planet creation. Star are made up of mostly hydrogen, helium and light. Stars as well contain a little amount of more massive elements, like iron. Stars with a greater metallicity have a higher chance of hosting planets, and the planets that they receive tend to be more massive than some of the lower-metallicity stars. It has also been discovered that stars that host planets are much more likely to lack in lithium.
3.1 Backwards Orbit
More recently an astonishing find has created a notable challenge that goes hand in hand with the existing theories of exoplanet formation; astronomers have uncovered a few transiting exoplanets that are actually orbiting in the complete opposite direction of the stars that host them. Astronomers have long concluded the theory that exoplanets form in a disc of gas and dust that encircles a star and therefore said planets orbit their host stars more or less in the identical direction as the stars’ own rotation. Complementary patterns are also observed with planets inside of our own Solar System. However this rule is broken and not followed by some more recently discovered exoplanets.
3.2 "Hot Jupiter" Planets
While some hot Jupiter exoplanets, meaning an exoplanet that has a mass that is like Jupiter or ceases it, were proven to be “misaligned” with the rotation axis of their host stars, other exoplanets were orbiting their parent stars in the “wrong” direction. As many researchers further their research, they have come upon giant exoplanets that are made up of what appears to be gas, which would be unable for humans to live on, but the other possible lifeforms could be adapted to the planets they live on. These “aliens” that could be alive on these gas planets could be classified as gas “aliens”. The other lifeforms that could possibly exist there would have to survive by consuming, something. They could possibly consume the power of lightning storms that are continuously raging on such planets as gas. If such extreme lifeforms are possible, than life elsewhere in the universe could very well be quite common. In reality, it seems with the possibilities such as these that there truly could be life almost everywhere we look, even if we don’t know it. Many scientists don’t actually have as much interest in what these other lifeforms are made of, but rather, what they can actually do that counts.
3.3 Why Life on Earth?
One of the most interesting questions that scientists have constructed with all of this information is: of all these billions and billions of planets within our solar system, why does our planet seem so unique? Could their truly be more earths out there that the world just haven’t been discovered because of how distant they could be? What makes our planet seem like one-in-a-million? With all of these questions, astronomer’s hope to answer these questions as quickly as they can. So many unanswered questions still exist involving the properties of exoplanets. One prevailing mystery is that transiting exoplanets, transiting is a method when a planet crosses (transits) in front of its host star’s disk, then the examined visual brightness of the star plummets a little bit, The extent that the star dims depends on the relative sizes of the star and its exoplanet, are quite greater than expected because of their mass, meaning they have an extremely low density. Numerous theories have been put forward to explain this observation, but have so far failed at getting astronomers to fully believe. Another question is how rational it is for exoplanets to possess their own moons. Moons have not yet been discovered, but they could very possibly be rather normal. Possibly the most intriguing question about exoplanets when it comes down to it, is whether or not any of them have the ability to support some form of life. Many planets have orbits within their host star’s livable area, where it seems to be quite agreeable for possible water to prevail and for Earth-like circumstances to occur. Several of these planets are massive like Jupiter as compared to Earth; if any of the exoplanets contain their own moons, than it would be plausible for them to support life rather than the planet itself. Gliese 581 g, en exoplanet that appears to be a rough planet that is going around the middle of it’s star’s livable area, was found in around September of 2010 and could possibly be the most “Earth-like” planet found until further research proves differently. Several guesstimates have been formed as to the number of planets that could possibly inhabit life or even greater intelligent life. For example, Dr. Alan Boss of the Carnegie Institution of Science makes a guess that there may possibly be around one hundred billion extraterrestrial planets just within our own galaxy, many with possible life. He also believes that there could be thousands upon thousands of living life spread throughout our galaxy. More recent studies acquired from Edinburgh University also has attempted to estimate the number of intelligent civilizations that could be within our galaxy. This research insinuated that there could be more than thousands of them. Separate from the scenario of extraterrestrial civilizations emitting powerful signals, the uncovering of life at far from reach distances is an extremely difficult and challenging goal that will not be achieved for many years to come, even if greater life is rather common. One thing that researchers and astronomers will never do, is give up. It is their faith and their pride in what they do that gives them the motivation to find answers to all of these unsolved mysteries that are involved with our Solar System.
Table of Contents
1 Extrasolar Planet
An exoplanet, or also called an extrasolar planet, is a planet that appears within our own Solar System and circles around a star that is varying from the Sun. The prevailing numbers of planets that have been discovered are planets that are consisted of mainly gases, because they are simpler to discover rather than planets that are more like Earth. Detecting these extrasolar planets are probably the most difficult to perceive because they are not seen by the naked eye, therefore making it quite tough to achieve finding them. The difference between exoplanets and the planets inside of our solar system are that most planets are capable of being viewed through at least a telescope, with the naked eye, without the means of some greater viewing capability that is greater than just a regular telescope. Just exactly how do we detect an exoplanet? This process is extremely difficult and has taken quite a long time to detect, even with our latest and most up-to-date technology. An orbiting exoplanet lets off a gravitational force onto its host star; it cause a force that tugs the star in a round or egg-shaped course. The most efficient method scientist’s use is the Doppler Planet Detection Method. This method involves breaking down the wobbling a star has in its movement. Now, before getting too caught up in learning about exoplanets, it’s time to explain just exactly how and when these extravagant beings came to be.
2 Methods for Finding Life
Life on exoplanets is a whole new story. It is almost “impossible” to be able to guess whether or not there is life on these amazing discoveries. There are several methods that scientist’s use to search for life. A few methods are used to spot the possibility of liquid that could thrive on exoplanets. A method used is called spectroscopy; this can show the characteristic absorption wavelengths of liquid molecules. This method actually has been used and worked successfully on giant solar planets that can be reached from reasonable distances from Earth. Other methods that are used include seeking for the appearance of clouds or the tiniest of light that shines off of a reflective surface from the planet. Although, this method has only been utilized for other types of liquids, such as the methane that is on the moon Titan, which circles around our planet Saturn.
2.1 Recent Study Methods
A more recent method that has been discovered could help further the great search. This method, which involves studying how colors shift with an exoplanet’s rotation, could help in the quest for discovering extraterrestrial life. This design should boost the chances of finding exoplanets with oceans — and, therefore, with life. “Since water is thought to be a prerequisite for life, we have effectively proposed another test for habitability,” said scientist Nick Cowan, from the University of Washington in Seattle. The researchers involved with creating this method developed it using data from Deep Impact, which is a NASA space probe that was launched in January 2005 to study the composition of a comet orbiting the Sun. Following the success of Deep Impact a few months later, it was sent on an extended mission to study another comet as well as distant exoplanets. During this extended mission, Nick Cowan and his colleagues used the “high resolution imager” telescope on Deep Impact to examine Earth from a few tens of millions of miles, as though our planet were an exoplanet.
2.2 Study Methods Involving Earth
The primary color of Earth is grey with a bit of blue due to Rayleigh scattering of sunlight off of the atmosphere. However, the researchers found that where the sky is clear of clouds that the average color changes with the Earth’s rotation. Whenever the continents are in view, the color alters towards the red end of the spectrum, and when the sea is in sight, the color alters even more so into the blue. With these transitions of color scientists should be able to reveal and locate oceans on real exoplanets. “The upshot [over the other methods] is that we don’t need very much spectral resolution — a few different filters would suffice — but we need pretty short exposures so that we can track time-variability,” Nick Cowan said. However, to able to view possible oceans on Earth-sized exoplanets, with the closet being at least several light years away, astrophysicists need a much larger telescope to be able to fully complete their project.
2.3 A Greater Telescope
The telescope to be able to view exoplanets would need to be massive enough and possess a corona-graph to block out the light shining from the exoplanet’s host star. But there might be a greater possibility to see oceans on giant Earth-sized exoplanets. Researchers hope to achieve building such a telescope by around the year 2017. A group called New Worlds will assemble a giant, 4m diameter telescope, with a very large corona-graph, to be able to specifically work with the detection of exoplanets.
3 Orbits of Exoplanets
Another exquisite quality that exoplanets have is the source that they use for their own “sunlight”. Each exoplanet that comes inside of our Solar System begins to orbit around a star that is within our own. Researchers even refer to these planets with the name “Alien” simply based on them coming from unknown places. Most exoplanets orbit stars close to the Sun. Observations have shown that stars of certain spectral categories, that stars of certain special categories, that are much warmer than even the Sun, produce a photo-evaporation affect that contributes to planet creation. Star are made up of mostly hydrogen, helium and light. Stars as well contain a little amount of more massive elements, like iron. Stars with a greater metallicity have a higher chance of hosting planets, and the planets that they receive tend to be more massive than some of the lower-metallicity stars. It has also been discovered that stars that host planets are much more likely to lack in lithium.
3.1 Backwards Orbit
More recently an astonishing find has created a notable challenge that goes hand in hand with the existing theories of exoplanet formation; astronomers have uncovered a few transiting exoplanets that are actually orbiting in the complete opposite direction of the stars that host them. Astronomers have long concluded the theory that exoplanets form in a disc of gas and dust that encircles a star and therefore said planets orbit their host stars more or less in the identical direction as the stars’ own rotation. Complementary patterns are also observed with planets inside of our own Solar System. However this rule is broken and not followed by some more recently discovered exoplanets.
3.2 "Hot Jupiter" Planets
While some hot Jupiter exoplanets, meaning an exoplanet that has a mass that is like Jupiter or ceases it, were proven to be “misaligned” with the rotation axis of their host stars, other exoplanets were orbiting their parent stars in the “wrong” direction. As many researchers further their research, they have come upon giant exoplanets that are made up of what appears to be gas, which would be unable for humans to live on, but the other possible lifeforms could be adapted to the planets they live on. These “aliens” that could be alive on these gas planets could be classified as gas “aliens”. The other lifeforms that could possibly exist there would have to survive by consuming, something. They could possibly consume the power of lightning storms that are continuously raging on such planets as gas. If such extreme lifeforms are possible, than life elsewhere in the universe could very well be quite common. In reality, it seems with the possibilities such as these that there truly could be life almost everywhere we look, even if we don’t know it. Many scientists don’t actually have as much interest in what these other lifeforms are made of, but rather, what they can actually do that counts.
3.3 Why Life on Earth?
One of the most interesting questions that scientists have constructed with all of this information is: of all these billions and billions of planets within our solar system, why does our planet seem so unique? Could their truly be more earths out there that the world just haven’t been discovered because of how distant they could be? What makes our planet seem like one-in-a-million? With all of these questions, astronomer’s hope to answer these questions as quickly as they can. So many unanswered questions still exist involving the properties of exoplanets. One prevailing mystery is that transiting exoplanets, transiting is a method when a planet crosses (transits) in front of its host star’s disk, then the examined visual brightness of the star plummets a little bit, The extent that the star dims depends on the relative sizes of the star and its exoplanet, are quite greater than expected because of their mass, meaning they have an extremely low density. Numerous theories have been put forward to explain this observation, but have so far failed at getting astronomers to fully believe. Another question is how rational it is for exoplanets to possess their own moons. Moons have not yet been discovered, but they could very possibly be rather normal. Possibly the most intriguing question about exoplanets when it comes down to it, is whether or not any of them have the ability to support some form of life. Many planets have orbits within their host star’s livable area, where it seems to be quite agreeable for possible water to prevail and for Earth-like circumstances to occur. Several of these planets are massive like Jupiter as compared to Earth; if any of the exoplanets contain their own moons, than it would be plausible for them to support life rather than the planet itself. Gliese 581 g, en exoplanet that appears to be a rough planet that is going around the middle of it’s star’s livable area, was found in around September of 2010 and could possibly be the most “Earth-like” planet found until further research proves differently. Several guesstimates have been formed as to the number of planets that could possibly inhabit life or even greater intelligent life. For example, Dr. Alan Boss of the Carnegie Institution of Science makes a guess that there may possibly be around one hundred billion extraterrestrial planets just within our own galaxy, many with possible life. He also believes that there could be thousands upon thousands of living life spread throughout our galaxy. More recent studies acquired from Edinburgh University also has attempted to estimate the number of intelligent civilizations that could be within our galaxy. This research insinuated that there could be more than thousands of them. Separate from the scenario of extraterrestrial civilizations emitting powerful signals, the uncovering of life at far from reach distances is an extremely difficult and challenging goal that will not be achieved for many years to come, even if greater life is rather common. One thing that researchers and astronomers will never do, is give up. It is their faith and their pride in what they do that gives them the motivation to find answers to all of these unsolved mysteries that are involved with our Solar System.
4 Observatories and Methods
5 Top Astronomers
6 Missions
6.1 Current
6.2 Under Development
6.3 Proposed
7 Classifications
8 Pictures of Exoplanets
9 Animation
10 Sideshow
11 Resources
http://exoplanets.org/esp/epseri/epseri.shtml
http://science.nasa.gov/astrophysics/
http://www.planetary.org/programs/projects/catalog_of_exoplanets/
http://www.cfa.harvard.edu/__
http://science.nasa.gov/science-committee/members/dr-alan-p-boss/
http://www.google.com/search?hl=en&client=firefox-a&hs=Wmt&rls=org.mozilla:en-US:official&defl=en&q=define:Exoplanet&sa=X&ei=i41iTda_KsKqlAfQ8cXMBQ&ved=0CBsQkAE
http://exoplanets.org/exoplanetlinks.html
http://media4.obspm.fr/exoplanets/
http://www.brahmand.com/news/Exoplanets-orbiting-host-stars-in-reverse-direction-found/3636/1/10.html
http://physicsworld.com/cws/article/news/39256
http://exoplanet.eu/star.php?st=Gl+581
http://planetquest.jpl.nasa.gov/
http://www.sciencedaily.com/news/space_time/astrophysics/